Record command lines in objects built by clang, LLVM part

[zhizhouy]

Summary

This patch is the LLVM part of the differential:
Link

If -grecord-gcc-switches is set, DW_AT_producer will be combination of DICompileUnit::Producer and Flags.

Also considering if it is good to create a new dwarf variable like DW_AT_flags to store the command line options.
Since on Darwin, it will create a DW_AT_APPLE_flags to store options.

[george.burgess.iv]

Thanks for working on this!

Please add one or more tests for this new behavior.

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

429

Looks like we're creating a StringRef to a temporary string here, which will give us undefined behavior when we use it on line 431. Please see http://llvm.org/docs/ProgrammersManual.html#llvm-adt-stringref-h .

[aprantl]

This needs a testcase.

[zhizhouy]

Fixed StringRef related problem.

Added a testcase for it.

[zhizhouy]

Moved test into test/DebugInfo/X86.

[echristo]

LGTM.

[echristo]

Committed thusly:

echristo@athyra ~/s/llvm> git svn dcommit
Committing to https://llvm.org/svn/llvm-project/llvm/trunk ...
A test/DebugInfo/X86/debug-info-producer-with-flags.ll
M lib/CodeGen/AsmPrinter/DwarfDebug.cpp
Committed r299038

[george.burgess.iv]

(Committed as noted by echristo; just trying to clean my queue a bit. :) )

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
   // LTO with assembly output shares a single line table amongst multiple CUs.
   // To avoid the compilation directory being ambiguous, let the line table
   // explicitly describe the directory of all files, never relying on the
   // compilation directory.
   if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
     Asm->OutStreamer->getContext().setMCLineTableCompilationDir(
         NewCU.getUniqueID(), CompilationDir);
 
-  NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
+  StringRef Producer = DIUnit->getProducer();
+  StringRef Flags = DIUnit->getFlags();
+  if (!Flags.empty()) {
+    std::string ProducerWithFlags = Producer.str() + " " + Flags.str();
+    NewCU.addString(Die, dwarf::DW_AT_producer, ProducerWithFlags);
+  } else
+    NewCU.addString(Die, dwarf::DW_AT_producer, Producer);
+
   NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                 DIUnit->getSourceLanguage());
   NewCU.addString(Die, dwarf::DW_AT_name, FN);
 
   if (!useSplitDwarf()) {
     NewCU.initStmtList();
 
     // If we're using split dwarf the compilation dir is going to be in the

test/DebugInfo/X86/debug-info-producer-with-flags.ll

+; RUN: llc -mtriple=x86_64-unknown-linux-gnu %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
+;
+; Test the DW_AT_producer DWARG attribute.
+; When producer and flags are both given in DIComileUnit, set DW_AT_producer
+; as two values combined.
+;
+; The test splits into two parts, this is LLVM part. The frontend part can be
+; found at llvm/tools/clang/test/Driver/debug-options.c.
+;
+; Generated and reduced from:
+; clang++ -g -grecord-gcc-switches test.cc -S -llvm-emit -o -
+;
+; test.cc:
+;   int main() {
+;     return 0;
+;   }
+
+; CHECK: DW_AT_producer
+; CHECK-SAME: "clang++ -g -grecord-gcc-switches test.cc -S -emit-llvm -o -"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @main() !dbg !6 {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, i32* %retval, align 4
+  ret i32 0, !dbg !10
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang++", isOptimized: false, flags: "-g -grecord-gcc-switches test.cc -S -emit-llvm -o -", runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "test.cc", directory: "d")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!"clang"}
+!6 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 4, type: !7, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DILocation(line: 5, column: 3, scope: !6)